


Jaeger on Autopilot

by njckle



Category: Big Hero 6 (2014), Disney - All Media Types, Pacific Rim (2013)
Genre: Alternate Universe - Pacific Rim Fusion, Gen, Hamada Brothers, Jaegers (Pacific Rim), Kaiju (Pacific Rim), Neural Handshake, The Drift (Pacific Rim)
Language: English
Status: Completed
Published: 2015-04-15
Updated: 2015-04-15
Packaged: 2018-03-23 01:56:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,679
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3750580
Author URL: https://archiveofourown.org/users/njckle/pseuds/njckle
Summary: <blockquote class="userstuff">
              <p>Co-pilots were often irreplaceable, brothers even more so.</p>
            </blockquote>





	Jaeger on Autopilot

**Author's Note:**

> Ever since hearing about this AU on Tumblr, I've been obsessing over it and planning a fic. Though it panned out a bit longer than expected, I'm pretty satisfied with it. 
> 
> Be prepared for some Pacific Rim lingo.

“You ready to kick some butt, nerd?” Hiro called, rolling his shoulders, trying to get the feel of movement with his suit on.

“Of course.” Was the calm reply, Tadashi’s voicing popping up in his comm despite standing barely three feet from the young boy, “Let's just hope you’ll be able to keep up.” The young man did a small stretch before stepping into place, Hiro following suit.

The mechanics at their feet clicked and the spinal clamps tightened (they always made Hiro want to twist and turn, his back itching), connecting their suits to Baymax’s interface. Hissing and humming filled the interior of the room, gears beginning to turn and grind, a small vibration ringing throughout it and into Hiro’s bones.

Weight pressed down on him as they slid down to the rest of the Jaeger. A small thud and they were connected, the sounds of bolts being snapping into place from all sides.

As the holograms lit up, indicating the machinery finishing its scans, Hiro rolled his eyes, “Says the senior in the room.”

More holograms popped up, displaying two full sized body diagrams, one purple and the other green. Hiro glanced at his brother’s, taking in the usual stats- heart rate, hormone levels, oxygen intake, and body temperature were all there, normal and average.

“Is that lip I’m getting from you?” Tadashi joked, offering a sly smile, “You know what, I’ll know in a couple of seconds so don’t bother answering.”

Hiro grinned, “Ready to get in my head, nerd?”

He got a laugh in response, “It’s you who I worry about.”

“Alright boys, now it’s time to focus.” Callaghan’s voice rang out from their comms, stern and demanding obedience.

They sobered up as Tadashi replied with a curt, "Copy that, Marshall," and became quiet, waiting.

The drift began with a suction feeling, like Hiro’s mind was being pulled in a vortex, draining from his head. There was always that moment of fear (where the stray thought of never coming out was overbearing) before he met his brother’s mind in the very center. It was almost like an explosion, their minds colliding and swirling together, merging into one. His thoughts and memories were Tadashi’s, vice versa- many of them were the same, if only from a different height and angle, but with different feelings.

And then Hiro was thrown back into his head, but not entirely the same.

The link that connected him to his brother was ever present and comforting; anything could trigger a memory, Hiro finding himself running through his brother's consciousness. Glimpses of images and scenes of him and Aunt Cass and the Lucky Cat emerged, along with echoes of joy and pride and sadness.

Words were no longer necessary, everything out in the open in the Headspace.

Letting out a deep breath, Hiro brought up his right hand just as Tadashi lifted his left. He knew even as he was grinning like a fool that his brother was doing the same. And when Hiro pounded his fist with his own and felt his brother do the same next to him, the sound of a resonating clang of large metal fists only made him smile wider. The explosion sounds, like always, were mandatory, accompanying the finale of their Neural Handshake.

 _"Synchronized."_ Baymax, the A.I., monotonously relayed, _"Neural Handshake: completed."_

The Hamada Brothers were in business and it was going to be…

“-sick.” Their voices rang out, synced and audible over the gradual increase in their generator’s power as the Jaeger finally woke up.

“Alright, Baymax, let’s do this.”

* * *

 The air was forced out Hiro's lungs as his metal body was shoved by the monster, the outer layering dented and warped and damaged. Iron and steel was nothing compared to Kaiju claws and teeth, the scrapes and scratches and cracks speaking for themselves.

With a roar, the monster slammed at them again, more agile in the water than they were in their bulking metal behemoth. Before they could grab hold of it, it was diving into the water’s depths to their right, the foaming waves and pouring rain hiding the monster. They lunged down in a last effort, but their giant hands held nothing, only water slipping through.

That wasn’t good. Rule #267: Always keep a Kaiju in sight.

Something rammed into their feet, gone before they could stomp on it.

Hiro heard Tadashi grunt at the force, both of them jarred as the waves crashed into them, unbalancing them even further for a precious second. Thankfully, the stabilizers flared out from their back, keeping them from toppling backwards into the sea.

Their lights roamed over the water, catching no glimpse of the Kaiju.

“Right hand to throat!” Tadashi called out, his order urgent as their sensors detected the Kaiju with a red marker at the corner of their vision. Hiro nodded, already raising his fist and pulling back; it was high time they gave this Kaiju a beat down.

Just as the Kaiju exploded from the water, claws out and ready to destroy, they struck, elbow rockets doing their job. The beast’s roar was cut off, strangled at the end as it’s over-protruding jugular was met with graphene knuckles.

Hiro whooped and cheered as they delivered an uppercut and then another right-hook.

Tadashi didn't share his feelings, pulling Hiro back from his childish behavior (but Hiro did see and feel a shadow of a smile). They got in a few more hits, even managing to dislocate the creature's shoulder; punch after punch, they weakened the Kaiju.

Soon it became a usual fight for them, the Kaiju roaring and slashing out at empty space and taking to the defense. But, it got scared and wilder and reckless. And it did what the loser in any fight did when faced with defeat and certain death: cheat.

Hiro was reminded of his bot fights and the less respectable opponents he defeated (those who couldn't handle being beaten by a kid). He should've been more cautious.

But where he wasn't, Tadashi was. His brother reached forward and punched in a quick code.

“Missile launcher.”

The Kaiju went down again, creating a tidal wave, evading two of the missiles, but having the last explode in its face. It roared in pain, shaking its head left and right, before blindly charging.

“He’s coming in on your side, buddy.”The young genius was already complying to his brother’s unspoken command, turning and grabbing at the Kaiju with his left hand. They barely caught the neck, it’s snapping jaws almost clamping down on their head armor. Hiro grimaced at the view of the inside of the Kaiju’s mouth, its tongue lolling about; with blue saliva and blood dripping and spraying everywhere, it was more disgusting than cool.

With a squeeze of their hand it stopped its snarling, forearms awkwardly coming up to try and release itself from their iron grip. Something close to resembling a whimper came out its mouth, albeit very deranged.

About to laugh, Hiro stopped as the Kaiju suddenly stilled. He looked on in confusion as the monster went limp in their hold. He shared a look with Tadashi, who was frowning as well.

"Wha-"

Before they could do anything the beast jerked to life, surprising them. It struggled and shook, twisting like a snake in a last effort to break free of the metal surrounding its neck. They kept their hold, Hiro shaking when the strain grew, unsure how long he could keep his hand up. One or two of their Jaeger’s fingers snapped off.

They'd dealt with overly energetic Kaijus before, and had gone through similar grapples. Together, Hiro and Tadashi made to grab a flailing arm, intending to rip it off. Only the Kaiju was undeterred, wriggling while they struggled to get a strong enough hold.

Whether it was do to their surprise or the water and the rain, it didn't matter- the unthinkable happened.

Their grip slipped and the Kaiju broke free, swatting away their arm grappling with its clawed one, and lunged forward-

-and crushed Hiro’s arm.

He screamed and the Jaeger screamed alongside him- alarms wailing, while the gears and joints screeched like a banshee. The Kaiju kept on crunching on the arm barely holding it back, ravaging it until it was barely recognizable.

Hiro doubled over, clutching his arm and cradling it to his side, Tadashi’s concerned voice muffled and distorted. His arm was on fire, his veins burning from his fingertips to his shoulder; it went limp, unable to follow his commands, all the while pain coursing through it. When the Kaiju fully ripped the metal appendage off, pulling it straight out of its socket, Hiro's pain tripled and he struggled to keep his hold on his disk.

“Hiro!” Tadashi called again, his voice suddenly becoming painfully clear and loud in Hiro’s ears. The entire Jaeger shook with the weight of the Kaiju clinging onto it, Tadashi attempting to stay standing. He somehow sounded panicked and calm at the same time, “I need you t-”

Groans and shrieks erupted above them as the Jaeger’s entire frame shook harder and more erratically than any earthquake San Fransokyo had had (even the cataclysm that preceded the Trespasser).

With wide eyes, Hiro took in a gaping mouth, no longer separated by metal and screens, but rather, only a few feet above him. Claws at the hole’s edge tore off more of the plating, the grated noise making Hiro cringe and his ears ring. Tadashi ducked, barely evading a falling armor plate.

Their armor was breached.

Something overtook him, overriding his senses and thinking, fogging up his mind. As his stomach dropped, his breath hitched and he found that his chest hurt. Suddenly, he couldn’t breathe no matter how hard he tried, his lungs failing him as the rancid smell of the Kaiju’s breath overwhelmed him. He body was shaking, not because of the chill from the outside.

Fear.

That’s what it was- he was afraid. So unbelievably afraid.

Terrified, in fact.

Because he was going to die.

There was no reason for this Kaiju to be different than any other one. No advantages or the sort. It was only a category two, nothing out of the ordinary. And yet, being average did nothing to stop the monster from killing them.

Hiro had heard about the countless pilots lost during Kaiju fights, but he didn't think he'd actually become one of the names on a long list of 'fallen heroes.'

But then, here he was, about to die to a low-leveled Kaiju, pathetic and small and scared...

Just as he was going to drown in his fears, a breeze came through, clearing the fog. Hiro gulped down a lungful of air, letting it out shakily; the calm washed over him, stubbornly pushing away his fears. He stopped his shaking and he found that his arm had numbed.

Tadashi was there to save him like like he always was.

"Hiro! I need you to listen!" Tadashi yelled, frantic, but still turned away from the Kaiju trying to force its way in. He kept eye contact with Hiro, holding him to the spot as the Kaiju raged on, "No matter what happens, you're going to get out out of this."

Hiro could only stare, feeling more like the 16 year old man-child he was than ever before. Another shake almost toppled him over and more chunks of metal were ripped apart, but Tadashi didn't waver or look away.

"Do you hear me? You're going to live." Tadashi's words were backed by his mind, giving Hiro nothing but faith and determination, "Don't you dare give up."

There was only time to nod jerkily before the claws above were replaced by jagged teeth and ripped skin, water pouring in along with it. The lower jaw smashed some tech without effort, but to Hiro's horror it went for the wires and levers connecting to the suits.

Just as the Kaiju’s teeth snapped at the machinery, Tadashi swiped his hand, taking full control from Hiro. Baymax complied with only a miniscule lagging time, its hand slamming into the monster's face. Hiro was rattled as the Jaeger was freed from its attacker; he watched the Kaiju’s jaws retract from the gaping hole, taking along with it parts of Baymax-

-and Tadashi.

Without so much as a yell, the young man was yanked up and out. Hiro only caught a glimpse of a surprised and fearful expression and arms uselessly reaching out before his brother was out of sight.

Wait, no, no, no… That wasn’t- he wasn’t-

"Tadashi!"

After a brief flare of pain, the connection to his brother was cut short, leaving Hiro truly alone.

The fear from earlier came back full force while he continued to stare at the hole where his brother disappeared. Tadashi couldn't have just been taken from him after his promise of safety. Hiro didn’t want to believe it, not that abruptly.

“Tadashi...?”

But it happened and the biting wind from the hole above and the empty space besides him told him of the reality.

Tadashi was gone.

“No! Give him back!” His fear suddenly turned into anger, then rage; the burning sensation was far more powerful than the pain earlier, overriding his system and fueling his failing body. The Kaiju had taken his brother away and he wasn't going to let that stand.

Not while he was alive.

There was a chance. A small, unbelievably miniscule chance that he would live- and if he didn't, then he was going to take the horrible monster with him. Either possibility was fine with Hiro.

He had to look at this horrible mess from a new angle and work with it.

And so, he spurred into action.

With no easy amount of effort, the main controls switched to his left hand (Baymax was his to control and his alone). Feeling faint and exhausted, he brought his hand back, hissing at the strain. His head felt like it was going to explode, the pounding behind his eyes getting stronger and more uncomfortable as the seconds passed.

Once he heard a loud click and a clang, he knew the metal arm had reached its full length. Wheezing, he locked his hand, body shaking for something that had been so easier earlier, “Initiate rocket fist.”

The whirring of the thrusters started immediately, its capacitors charging much faster than ever before. Hiro didn’t bother with the chances, nor did his brain feel up to the task of calculating the probability of the charging time shortening within the limited time period since its last upgrade. All he cared about was the Kaiju in front of him and how it wasn’t dead and floating in its own guts.

The Kaiju stumbled back into his view, metal parts prominent between its teeth. Hiro ignored the pain and the black spots appearing in his vision, only focusing on the shot.

“You,” He panted, feeling lightheaded, “don’t just get to take him... Not Tadashi. Not while I’m here.”

Even as the monster started to charge through the water towards him, he kept his stance. For a moment, the pressure on his head lessened and his hand didn't feel as heavy, his vision cleared, and he felt strangely calm. His confidence in his aim returned (even more precise than ever before), the fist launching with a jerk of his arm just as the Kaiju leaped above the waves.

There was no hope for it, as the fist hit its already damaged neck. It went down easy and without a fuss. Bits of flesh flew into the ocean while blue blood spilled from the wound, the Kaiju stumbling back and crashing down into the water.

It didn't resurface.

Hiro panted, holding up his arm long enough to for Baymax's fist to return and attach itself. He dropped the main control and slumped forward, unable to do anymore and wanting to sleep. The black spots appeared again, this time slowly  taking his entire vision.

And then his brain shut down, with a small voice whispering that he didn't have to worry about piloting anymore.

* * *

 Looking between the expectant adults in front of him to the eager faces of potential candidates lined behind them, Hiro knew he didn’t want to go through with this. Despite the hundreds of times he’d annihilated whoever he was matched up against, he suddenly didn’t want to go near the compatibility test, didn’t want to put his mind against someone else’s.

No one else would even come close to qualifying.

He’d never felt smaller, facing people twice his size, all of whom had eyes freezing him in place (coming for the chance to co-pilot alongside the youngest Ranger who miraculously solo-piloted a Jaeger back to base, something he didn't remember). Silently, he shook his head, refusing to come closer to the testing controls, nor would he put on the neural cranial transmitter.

Callaghan sighed, “Hiro, we have to proceed with the testing.” He offered the headpiece, only for the young genius to step back, “You need another co-pilot.”

He shook his head again. It didn't matter that Callaghan was looking at him with a disappointed look. Nor did it matter that the other higher ups in charge were watching with increasing impatience. If they thought he was being a spoiled brat, he didn't care.

Tadashi was his co-pilot and that was final.

“Hiro, can you just listen to us?” Honey Lemon, ever sweet and motherlike, stepped forward to be as close to him as she dared (Hiro didn't try to stop her). She and the rest of the gang were more Tadashi’s friend than his, his brother knowing them from his time in the research division. Hiro didn’t know why, but they seemed to be plowing right on through as if nothing had happened- that Tadashi wasn't gone and dead and never coming back. The blonde tentatively gripped his shoulder and Hiro stared at her, “We know how horrible this must be… we miss him too- we really do… but-”

“-you need to woman up and move on.” GoGo offered her usual TLC, earning a glare from Honey. Usually, Hiro appreciated her uncaring and blunt nature, but now he wanted to hear none of it. He’d rather deal with Fred’s incessant Kaiju squealing and Wasabi’s narcotic ranting than hear it.

He wasn’t listening- he wouldn’t listen. A small part of him cheered as he shrugged off Honey's hand and glared down all the adults, putting all his anger and stubbornness into it; whatever they wanted he would refuse, he decided then and there. There was no way these people, who knew nothing about him or Tadashi or Baymax or the Hamada Rules- or anything really, were going to force him to replace his brother. If they were too stupid to see that, well, he would have to show them.

Ignoring the commands and pleads alike, he turned and stomped out of the room without another word. Once out of sight, he bolted, running to the only other thing left in his life that mattered.

* * *

The elevated ramps surrounding Baymax was clear of all personnel, the remodeling and repairing on the behemoth finished weeks prior. Hiro was glad; sitting there seventy feet above the ground, staring at his Jaeger face-to-face, he needed the silence and isolation.

Instead of talking, he opted to take in everything about the Jaeger. Despite the repairs, scuffs and scratches covered most of the faded red and purple plating of the machine, some of the metal was still chipped at its torso and thick wrists. Compared to the other Jaegers, Baymax was broader and shorter, looking like one of mechas Hiro had often seen on the numerous TV shows that were often played back at the Lucky Cat Café. The young genius eyed the black optics looming over him, only to wonder whether they were online or not and had any idea what was happening.

He stared up at the robot and dug his palm into his eye socket when he felt the burning sensation of tears. There was no way he was going to deal with that right now.

“Sorry, Baymax…” Hiro whispered, trying to keep it together. He sniffed and continued to rub at his face, not wanting any random pilot or mechanic to catch him in such a pathetic state (not after the scene he created earlier), “I'm t-trying- but with everything that's going on... ”

Hiro didn’t like how his bottom lip was shaking uncontrollably or how he couldn’t control the rest of his face. No matter how hard he tried to push them back, the tears leaked through, “Tadashi's... gone... and now they want to replace him...”

He looked at the Jaeger again, searching for something that could reflect his brother, but only finding an unresponsive machine (don’t worry, Baymax will be there to take care of you). Nothing that represented his caring, responsible brother. How could that be when Tadashi had put so much into it (didn’t use the regular Jaeger coding, so he’s a bit different than the others) How could he have put so much hope and trust (he’s not going to fritz on us, Hiro... well, I’m pretty sure he won’t) into it?

Along with the memories came the anger, this time directed toward the big bulk of machine standing innocently in front of him, “Why didn't you protect him? What kind of Jaeger lets their pilot die?"

He didn't get a response, but, then again, he shouldn't have been expecting one. His anger deflated, gone as quickly as it came. Blaming the robot wasn’t helping anyone, least of all him. Really, he was more to blame than Baymax.

What kind of pilot was he to let his brother die?

* * *

 Taking in a deep breath, Hiro waited for his new co-pilot to arrive. He barely noticed the numerous mechanics that flitted about like hummingbirds to make sure Baymax was up and fully functional, their first drift after weeks of listless living and adapting.

He wasn't ready, but everyone else in the world was. A perfectly good Jaeger couldn't be kept out of service for long, the Rangers piloting them in dire need as well. It didn’t matter what he thought or wanted, or even what he was going through, everything would continue on.

Stepping up to his place, he didn't bother to wait. He was going to go through with this, but there would be no courtesies, fighting at every step.

Callaghan had gone and tested the candidates, using Hiro's previous results when he realized he wasn't going to get anything out of the genius. And now, Hiro had been paired with a complete stranger.

A part of him hoped that this would turn sour just to spite everyone. He was positive that it would fail. If it did, that wouldn't stop the higher ups from demanding he try and try again.

But it would always fail. Something as complex as compatibility wasn't something they could force on two people.

A shuddering sound rang out from behind Hiro, but he didn’t bother to twist and see what it was. The few straggling technicians and mechanics still present exchanged hushed words and exited the Jaeger, off to investigate. The gears under and behind Hiro went into motion.

He shifted, uncomfortable (in Tadashi's old spot, now his), the suit connecting and everything turning on and running like usual.

He waited.

The silence broke abruptly, muted pounding and yelling scaring Hiro. He craned his neck, noticing the closed hatch. There were people trying to get in, but nothing should've been stopping them, since it wasn't time to lock the hatch. Departure wasn’t until both pilots were in and ready. So why would...?

Without warning, Hiro was lowered down to the rest of the Jaeger, more rocky and unstable that it was supposed to be. He yelped, glad that he was held in place, his fear rising the farther he was lowered. _Something's wrong_ , he thought as he jerked to a stop, _something's happening_.

Everything around him was running without his help, the mecha giant coming alive. But that wasn't possible. Through the feed he had in front of him he saw the ramps and runways begin moving, frantic people stumbling and a few gripping on bars for dear life. That definitely wasn't supposed to be happening.

He tried to get through to everyone in the control room, receiving only static. There was no Callaghan or GoGo or Honey or anyone; they'd always been able to reach him, always with the random bantering of Fred and Wasabi in the background.

Just as he was just feeling a panic attack take over, words appeared on the screen before him, accompanied with a voice, _"Hello, I am Baymax, your personal Jaeger A.I."_

"What?" Hiro froze, blinking at the words shinning from the screen, confused. He'd heard the phrase and voice before, when Kaiju fighting and Jaeger piloting was new and Tadashi was alive and excitedly showing him something or someone.

_"Do you wish to continue?"_

“What?" It was bizarre, something that that he didn't expect. Baymax was only the interface of of the Jaeger, nothing more; he was there so that they could control the machinery, not to interact. For a moment it sounded as if he was responding Hiro, but that wasn't...

_"You are currently experiencing hyperglycemia and dyspepsia, as well as an increased heart rate. This status isn't healthy for a drift. Do you still wish to continue?_

...possible.

Hiro distantly remembered the moments with Tadashi, filled with over-the-top concern from his brother and constant complaining coming from him. Always with the questioning whether he could do this or that, his health a top priority. (Was he okay for another drift? He had just done a mission not two days before.)

Hiro found himself saying a small "yes" despite what his rational side was screaming at him, something compelling him.

_“Commencing: drifting sequence.”_

The buzzing in his comm died down, becoming distant to Hiro, as did the sounds around him. He stared forward without truly seeing, unblinking and frozen.

All that mattered was the strange, nostalgic sensation coming from the back of his mind.

He was pulled into the vortex that was the Drift.

_Static. The feed was frayed and choppy. Static. But, an expectant face was distinguish, brown eyes wide and hopeful. Static._

The memory wasn't human.

_The face was close. No static. So close that the sclera and an iris (brown- yellow, red, black) were prominent. Pliers were held between teeth. Wires cut a few inches, sparking, and resulted in a cry and rapid movement. Words- cursing, profoundly. Static._

No longer scared or confused, he was interested. There was no strain, no pain blossoming at the back of his head, and a presence somewhere told him he wouldn’t be feeling it while it was there.

He wasn't alone.

_There was more coding, more awareness. Consistent backgrounded was often seen, with worn machinery and differing people. Tadashi, the face’s name (and his creator’s), was a constant sight, always there to fix and work and help and smile. Spoke often, going on about a ‘Hiro’ and ‘knuckleheads’ and ‘Kaijus’ and a ‘Baymax.’_

Something flickered in his peripheral vision on his left, grabbing his attention. Tadashi’s face from the memory lingered in an afterimage, the onslaught of sights and sounds letting him be for a moment.

_He was a Baymax. That was his name. Baymax. Baymax, a ‘he’ and not an ‘it,’ because Tadashi stated it and coded it. Baymax. He was Baymax._

Next to him an incorporeal ghost wavered, taking a form that he recognized. A hologram, but more realistic than anything he’d seen before.

_Text-to-speech. Internal scanner. New upgrades. Production efficiency was high. Tadashi continued to speak to him, his newfound voice responding accordingly, with inquisitions. Erratic movement, a higher pitch, and rising in serotonin indicated happiness (a kiss to his lenses and a dance around the room). The ‘Hiro’ was brought up once more._

Black and white rather than purple, the suit was exactly as he remembered it. Even the stance was the same, everything about it mimicking Tadashi.

_He inquired, questioned, learned. He was artificial intelligence, made with codings and metal and a battery. He was an A.I. for a nursebot (Kaiju Blue was toxic and he would help). Tadashi changed, becoming less happy and more anxious despite his progress. The ‘Hiro’ was still prominent in conversations, although strained._

His co-pilot turned its head toward Hiro, visor blank and showing nothing. Although not materially present, the machinery behind it moved accordingly to its movements.

A fist was innocently offered.

_A somber expression greeted him, tired eyes and messy hair. A sad smile, Tadashi looking he wanted to laugh and cry at the same time (human expression indicated), “He passed the exam and now he’s off to fight Kaiju…” Tadashi ran a hand through his hair, looking at him, “and we’re going with him.”_

There was wetness on his cheeks, tears dripping down before the previous ones had time to dry.

_Strange features- more than just video feed- a body, he evaluated, complete with legs, arms, and a head. Intricate circuitry and parts made his entire being- not just wires, a motherboard, and hyperscopic lenses. A new background, the feed new and different. There was an inside and an outside, visuals of both. Tadashi was still there (inside), calling out to a ‘Hiro’ (outside)- Baymax was introduced. He discovered the ‘Hiro.'_

Suddenly, the hull of the Jaeger was far more familiar and inviting and the shuddering of the gears and levers were more calming than any words Aunt Cass could offer. The spinal clamps no longer itched uncomfortably and the helmet less suffocating, feeling like all of it had always been a part of his body.

Unconsciously, Hiro brought up his left arm, curling his hand into a fist.

_Tadashi and Hiro Hamada were his Rangers. He was named Big Hero, their Jaeger. He was permitted to act beyond safety measures. Tadashi asking for a confirmation in change in coding. New priority: protect Hiro Hamada at all cost. Accepted and confirmed. Coding changed._

His breath hitched and a new wave of tears come forth. The co-pilot’s head tilted, as if confused. A sad face appeared on its visor, questioning.

Hiro only shook his head, “It’s alright, buddy- I-I’m fine.”

And, surprisingly enough, he was.

_Location: 30° 36' 0.3379" N, 124° 16' 38.4375" W. Tadashi Hamada’s status: unknown, presumed dead. Hiro Hamada’s status: injured, presumed alive. Threat detected: Kaiju, level 4. Course of action: protect Hiro Hamda._

Then he was back in his head and the sound of their fistbumb rang in his ears.

"Y-you..."

_"-ou hear us? Our system's been breached and overrided. Baymax isn't shutting down. We're going to p-"_

"N-no! Don't do that! Everything's fine- we- I'm fine." Hiro hurriedly connected his comm, his voice far too croaky than he'd like. There was no way he was going to let them stop this, not when he was just figuring it out, "Just whatever you do, don't disconnect us."

There was a pause. Sounds of moving and rushed words came through, Hiro only half listening, watching Baymax replace his previous face with one with a blank expression, either annoyed or bored. A voice that wasn't Callaghan’s spoke through, bringing him back to his conversation.

_"Hiro! We've been trying to get through to you-"_

"I-I know, but you can't shut us down." Hiro wracked his brain, trying to think of something that would make them doublethink ending everything. Callaghan had let GoGo be the mouthpiece, so they were definitely worried and needed him calmed without problems. She sounded irritated, so he had to be quick and and it had to be big, "I think we're co-compatible."

_"You can't b- what do you mean 'we're compatible?' There's no one in there."_

"Yeah... me and, uh, Baymax."

A pause and then a growl, _"Hiro, I'm not in the mo-"_

"I'm not making this up! And this isn't a grief-induced illusion or anything like that! Baymax is active and we are compatible.

_"Explain. Now."_

"I-I don't know how but he's more self-aware than what... what Tadashi told us. But he is a-and he's offering to be my partner and..."

... he wanted to help. Baymax wanted to help Hiro, protect him. Even then, Hiro felt the alien presence of the patient A.I., sharing his simplistic concern and eagerness that he was all to used to.

_"And..? And what? Hiro, you better answer me!"_

"I-It's nothing. L-Look I'll try to explain later... Just please, don't shut us down… I’m begging you."

Another pause.

 _“I can’t believe this...”_ There was a sigh, followed by an uncharacteristically worried tone, _"Are you sure you’re f-?"_

"Yes... please GoGo. You won’t regret it. Trust me."

The silence that followed from her end had Hiro nervous. He was scared that he wouldn't get the chance to see this though. Wouldn't be able to see what Tadashi left him, gifted him from beyond the grave. And Hiro didn't want to lose something of his brother's before he got a chance to see what Baymax could do.

Hopefully, GoGo could convince Callaghan for him.

 _"Fine."_ Came the eventual reply, _"You have one chance, Hiro. But, if anything so much as looks like it's going wrong, we're taking you out. Got it?"_

Hiro glanced at the hologram, which displayed a smiley face, "We got it."

GoGo went on to give him guidelines and orders, stating that given anything less than what she was demanding and it would be over. Hiro could hear Fred in the background, having caught wind of the ‘self-aware Jaeger’ and pestering for a moment with Hiro. Bickering ensued, the voices of Honey and Wasabi trying placate the situation. Baymax cut the feed, momentarily displaying an angry face again before replacing it with its smiling counterpart.

_"This will be sick?"_

Following the Baymax’s question, Hiro felt like crying again. Instead, he swallowed back the feeling and nodded, "Yeah... it will be."

 

**Author's Note:**

> There are so many aspects of this AU that I didn't insert in.
> 
> Some AU Headcannons:  
> -San Fransokyo was the first city hit (by an unknown Kaiju named Tresspasser)  
> -Baymax was originally created to be a nursebot, but Tadashi modified him to be a Jaeger A.I. once Hiro was accepted as a Jaeger pilot (16 is age requirement)  
> -While the Jaeger and A.I. would be called Baymax by the Corps, the world would know him as Big Hero (despite Tadashi's protest, Baymax just wasn't heroic enough)  
> -Jaeger Baymax would look like a mix between the early concept designs done by Shigeto Koyama and the really cool fanart done by KM33 on Deviantart  
> -Compatibility testing involves a physical test as well as a mental test (a shout-out Hiro's neural transmitter, which he definitely made for the Corpse)  
> -Callaghan is a Marshall, GoGo and Honey are LOCCENT Officers, and Wasabi and Fred part of the K-Science Lab (respectively Hermann and Newt)
> 
> I have a bunch more headcannons, but that's for another time. Anyway, enjoy and feel free to leave a comment!


End file.
